Washington: Patients with language impairment due to Dementia have shown signs of reading and speech inefficiency, according to recent research. The study surveyed people whose mother tongue is either English or Italian. Researchers from the UC San Francisco Memory and Aging Center and Neuroimaging Research Unit and Neurology Unit at the San Raffaele Scientific Institute in Milan collaborated to conduct the language study.
Earlier neurologists had already believed that language abilities are directly influenced by various brain diseases. But recent discoveries have begun to question that assumption.
For instance, Italian speakers with dyslexia tend to have less severe reading impairment than English or French speakers due to Italian’s simpler and more phonetic spelling.
“Clinical criteria for diagnosing disorders that affect behaviour and language are still mainly based on studies of English speakers and Western cultures, said study senior author Maria Luisa Gorno-Tempini, MD, PhD.
“This could lead to misdiagnosis if people who speak different languages or come from another cultural background express symptoms differently,” continued Maria, also a professor of neurology and psychiatry and the Charles Schwab Distinguished Professor in Dyslexia and Neurodevelopment at the UCSF Memory and Aging Center.
“It is critical going forward that studies take language and cultural differences into account when studying brain disorders that affect higher cognitive functions — which we know are greatly impacted by culture, environment, and experience,” she explained.
The new study focused on patients with primary progressive aphasia (PPA), a neurodegenerative disorder.
It affects language areas in the brain, a condition often associated with Alzheimer’s disease, frontotemporal lobar degeneration, and other dementia disorders. The researchers recruited 20 English-speaking PPA patients from the UCSF Memory and Aging Center and 18 Italian-speaking PPA patients from San Raffaele Hospital, all of whom shared a variant of PPA characterized by difficulty producing or pronouncing words — so-called non-fluent PPA.
“We wanted to study patients with PPA to understand whether people from different language backgrounds actually experienced the disease differently, and what that might mean for how we try to help patients remain resilient to the disease,” said study lead author Elisa Canu, PhD, a neuropsychologist and researcher in the Italian speakers’s Neuroimaging Research Unit.
Cognitive tests and MRI brain scans revealed similar cognitive function and comparable levels of brain degeneration in the two groups. But when the researchers compared their performance on a battery of linguistic tests, they observed a key difference. English speakers had more trouble pronouncing words — the traditional hallmark of nonfluent PPA — and tended to speak less than usual. In contrast, Italian speakers with the same disorder had fewer pronunciation difficulties but tended to produce much shorter and grammatically simpler sentences.